The invention relates to a spray head for a mold spraying tool. The spray head includes a connecting piece which can be attached to a movable arm and has a plurality of through-passages each for the controlled feeding of the spray media, as well as with a connecting piece made up of connecting pieces extending out from the connecting piece across the direction of movement of the arm to connecting pieces leading to spray nozzles combined in spraying circuit groups and in communication through connecting passages to the through-passages in the connecting piece.
A spray head of this kind, which is of modular construction, is disclosed in U.S. Pat. No. 4,760,961. In it a spray head composed of variable vertical and horizontal columns has been created by a linear concatenation of a plurality of identical spray head modules, the arrangement of which lies substantially in a single plane. Any adaptation to the depth of the solid, confronting mold halves or of the movable mold halves, is not possible or possible only by the use of extension tubes for the nozzles. It is known that such extension tubes have a tendency when in constant operation to become offset from their position, so that certain disadvantages can occur in the spraying process.
EP 0 724 486 B1 discloses a spray head, wherein by the arrangement of spacing pieces the distance of spray plates from the movable arm in the direction of the mold halves can be variously configured. In addition to the adaptation of spray modules in plate form in planes running parallel between the mold halves, thus also the distance of the spray module arrangement perpendicular thereto, which is facing the fixed or movable mold, can be variously arranged. In this case too, however, the spray modules can be arranged largely arbitrarily only in their planes which run parallel to a central plane between the mold halves.
In all of the spraying tools known heretofore a plurality of spray circuits are provided, in which each of these spray circuits feeds any desired number of spray nozzles, which can be actuated independently of one another time-wise. The position of the spray circuits follows a pattern provided in the design phase. In the case of a spray tool having, for example, four spray circuits, the two odd spray circuits, i.e., spray circuit 1 and spray circuit 3 are facing the movable mold half and the spray circuits 2 and 4 spray the fixed mold half.
An object of the present invention is to construct a spray head of the kind named in the beginning such that both spray head sides, which thus are facing the fixed mold half in the one case and the movable mold half in the other, can be provided with spray nozzle arrays which lie in a plane running parallel to the center plane between the mold halves. Further, the spray circuits facing the individual mold halves can be made freely selectable.
To accomplish this object, provision is made in a spray head of the kind referred to in the beginning, such that the connection piece is constructed of a plurality of distributor blocks which can be placed one against the other in the direction of movement of the arm. Additionally, media-carrying passages branching transversely from all through-passages are arranged in a predetemined sequence and lead into both lateral surfaces. Further, connection plates which can be turned 180° can be placed on the lateral surfaces and are provided with at least one connecting passage which opens on the side adjoining the distribution block out of symmetry with the longitudinal central plane but in modular pattern of the mouths of the media-carrying passages. Moreover, on each connection plate the connecting pieces are connected up to the spray nozzles, so that each spray circuit group can be connected selectively to one of the through-passages and to the medium feed controlled therein.
With this configuration it becomes possible, for one thing, to associate only one spray circuit of four spray circuits, for example, with the fixed mold half, in order for example to spray certain mold parts successively or in groups or to blow them dry again with compressed air.
By dividing the connecting piece into several distributor blocks which are placed one under the other it becomes possible, by means of the connection plates which can be attached to the distributor blocks and possible elongations, to make the spacing of the spray nozzle groups from the distributor blocks different. As a result, the spray nozzle modules facing the movable mold halves will not be in a common plane running parallel to the central plane, but will be arranged sectionally under or over one another in planes that are at different distances from the moving arm and run from the associated distributor block placed on the arm. This configuration avoids the use of extension tubes and permits individual adaptation of the spray head modules to the mold halves plus the possibility of individually selecting the application of the spray.
In a further development of the invention, each connecting plate can be provided with two connecting passages which open asymmetrically from the longitudinal central plane. A flange block can be placed in front of the associated spray circuit group of spray nozzles, and used to select one of the two connecting passages as a supply passage for the spray circuit group.
In a still further development, connection blocks can be inserted optionally between the connecting plate and the flange block in order to adjust the spacing of the spray circuit groups. It therefore becomes possible to make all of the connection plates and flange blocks largely identical, and to achieve the spacing arrangement with junction blocks which also are of identical design. The parts necessary for the construction of the spray block therefore remain limited in number.
In an additional development, through-passages can be provided in each distributing block to carry drying air, and separate connection plates can be used for the connection of blast air nozzles. It thus becomes possible, as previously indicated, to blow-dry mold halves or even mold parts.
In a still additional development, the connecting blocks can be provided with through-holes which are symmetrical with a central longitudinal plane. The mouth connection of such symmetrical passages in the lateral surfaces thus becomes simple. In a development of the invention, each flange block can be provided with a connection passage which is arranged in the side adjacent the connecting block out of symmetry with a longitudinal center plane but spaced away from the through-bore in the connecting block. This configuration also permits the connection of a flange block in two positions 180E apart, so that in this manner a selection of a supply passage is possible.
In a yet additional embodiment of the invention, the spray nozzles that are combined to form a spray circuit group can be attached to a spray bar, which facilitates the assembly of the spray head. The spray bars can then be composed advantageously of a plurality of component units which are provided with media passages aligned with one another. Also the size of a spray bar can thus easily be built up individually.
The component units can then be provided with bent-away end portions, and the end portions can be formed by corner pieces which are attached to the end of straight units. This configuration then also makes it possible to construct the spray bars from spray bar parts set at an angle to one another, which further improves the possibility of adaptation to the mold halves.
In a still yet development of the invention it is possible that between a distributor block and a flange block one or more connecting pieces are provided for adjusting the distance of the spray circuit group from the central connecting piece. The previously mentioned adaptation of the spray circuit groups to the molds, which is possible by stacking them, can thereby be facilitated.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.